Nowadays, a projecting device (projector) is used for various purposes. For instance, the projecting device may be connected to a PC or a smart phone, etc. to project image information such as videos or still images stored in the PC or the smart phone, onto a preset screen. As the image information is displayed on a larger screen, the image information stored in the PC or the smart phone may be viewable by a larger number of users.
As the projection device is connected to a smart phone, etc. to project image information stored in the smart phone, it is possible to satisfy a user's desire to enjoy information stored in his or her mobile device with other users. However, when connecting the projection device to such a smart phone, user's personal information stored in the smart phone may be projected onto the screen. This may cause information to be exposed to other users against the user's will.
Further, the projection device serves to project pre-stored image information onto a single screen. This may cause the single screen not to be efficiently used, even if it is much larger than a TV or a PC monitor. Accordingly, research is being actively ongoing in order to solve such problems.